Comparison of Two- and Three-Dimensional Methods for Analysis of Trunk Kinematic Variables in the Golf Swing.

Smith, Aimée C.; Roberts, Jonathan R.; Wallace, Eric S.; Pui Kong; Forrester, Stephanie E.

Two-dimensional methods have been used to compute trunk kinematic variables (flexion/extension, lateral bend, axial rotation) and X-factor (difference in axial rotation between trunk and pelvis) during the golf swing. Recent X-factor studies advocated three-dimensional (3D) analysis due to the errors associated with two-dimensional (2D) methods, but this has not been investigated for all trunk kinematic variables. The purpose of this study was to compare trunk kinematic variables and X-factor calculated by 2D and 3D methods to examine how different approaches influenced their profiles during the swing. Trunk kinematic variables and X-factor were calculated for golfers from vectors projected onto the global laboratory planes and from 3D segment angles. Trunk kinematic variable profiles were similar in shape; however, there were statistically significant differences in trunk flexion (-6.5 ± 3.6°) at top of backswing and trunk right-side lateral bend (8.7 ± 2.9°) at impact. Differences between 2D and 3D X-factor (approximately 16°) could largely be explained by projection errors introduced to the 2D analysis through flexion and lateral bend of the trunk and pelvis segments. The results support the need to use a 3D method for kinematic data calculation to accurately analyze the golf swing.

ANALYSIS of variance; BODY weight; GOLF; KINEMATICS; REGRESSION analysis; STATURE; TORSO; REPEATED measures design; MOTION capture (Human mechanics); DATA analysis software; DESCRIPTIVE statistics; ONE-way analysis of variance

Journal of Applied Biomechanics, 2016, Vol 32, Issue 1, p23

1065-8483

Academic Journal

10.1123/jab.2015-0032